Hi and welcome. I've added a trigger warning to your post as you discuss suicide. It's nothing to worry about, it's just so others can make the choice to read your post if it will trigger them.

How long have you been on the sertraline? Is going on sick an option? Could you ask your doctor for counselling? Does your partner know how you feel? Sorry for all the questions.
There are plenty of helplines available if you desperately need someone to talk to. Please don't be afraid to use them, and we will support you as much as we can. You are not alone